If the trailer was made, or originally set up for your specific boat, then you may not want to mess with it. I have had to make adjustments to many a trailer to get the weight balance that worked best, (tongue weight has always been a major consideration when pulling with my light-duty van equipped with a class II hitch). Some trailers are actually made so that you could move the axle to one of 3 or 4 locations, whichever fit your needs best. Your Float On probably does not have that option.
HF boat dolly for $60 (or less with coupon): http://www.harborfreight.com/600-lb-heavy-duty-trailer-dolly-60533.html
Hardly worth fabricating one at that price.
HF boat dolly for $60 (or less with coupon): http://www.harborfreight.com/600-lb-heavy-duty-trailer-dolly-60533.html
Hardly worth fabricating one at that price.